Multiple disc clutches for engaging and disengaging coupled shafts during rotation are well known in the art. See, e.g., U.S. Pat. Nos. 1,886,865; 3,291,272; 3,317,013.
However, such prior art clutches are typically mechanically complex with complicated linkage mechanisms for accomplishing clutch engagement and disengagement. Also, prior art clutches usually require confined housings or other surrounding supporting structures that restrict optimum air flow around the various clutch parts, thereby limiting clutch life and efficiency by insufficient cooling and permitting buildup of unwanted heat.